Adapt existing php implementation of superfish dropdown menus

Estimated duration: not set
Description: superfish.js version 1.4.8 is called by menu.php which reads company names from a database and they are then displayed in ascending alphabetical order within alpha groups according to the first letter of the company name.

I need to modify the actions of menu.php so that it can be set up to search for and list companies in groups based on more than just the first letter of the company name.

It is important to retain the ability to modify the drop down by making changes ONLY to menu.php so that we can continue to modify it ourselves.

currently the Companies drop down segments as follows
A - B
C - D
E - G
H - K
L - M
N - O
P - R
S - T
U
V - Z

it needs to change to
A - B
C - D
E - G
H - K
L - M
N - O
P - R
S - T
U - USPB
USPC
USPD - Z

When cursor hovers on USPC user should see submenu #1:
USPC
USPC-A - B
USPC-C
USPC-D - Z

At this point another submenu needs to be added which displays the companies whose names begin within the selected range. Currently those names are part of the general 'U' level drop down.

As is currently the case, we must retain the ability to go into menu.php and adjust the exact breakdown of the range for each of the menu items, including the new USPC section, as more companies are added.

See attached txt file for full menu.php code